Tech Talk
Anyway, how much do you really know about the life blood of your car, the oil. Below is a brain tickler with perhaps some things you never thought about, or just plain didn’t know.
Enjoy
5W-30…What does it mean
It’s a measure of viscosity……an oil's speed of flow as measured through a device known as a viscometer. The thicker (higher viscosity) of an oil, the slower it will flow.
OK . . .What does a 5W-30 do that an SAE 30 won't?
When you see a W on a viscosity rating it means that this oil viscosity has been tested at a Colder temperature. The numbers without the W are all tested at 210° F or 100° C which is considered an approximation of engine operating temperature. In other words, a SAE 30 motor oil is the same viscosity as a 10w-30 or 5W-30 at 210° (100° C). The difference is when the viscosity is tested at a much colder temperature. For example, a 5W-30 motor oil performs like a SAE 5 motor oil would perform at the cold temperature specified, but still has the SAE 30 viscosity at 210° F (100° C) which is engine operating temperature. This allows the engine to get quick oil flow when it is started cold verses dry running until lubricant either warms up sufficiently or is finally forced through the engine oil system. The advantages of a low W viscosity number is obvious. The quicker the oil flows cold, the less dry running. Less dry running means much less engine wear.
Be careful with oils claiming to be Synthetic
Group IV (4) and Group V (5) base oil (synthetics) are chemically made from uniform molecules with no paraffin and don't need Viscosity Additives. However, in recent years Group III (3) based oils have been labeled "synthetic" through a legal loophole. These are petroleum based Group II (2) oils that have had the sulfur refined out making them more pure and longer lasting. Group III (3) "synthetic" motor oils must employ Viscosity Additives being petroleum based.
Group V (5) based synthetics are usually not compatible with petroleum or petroleum fuels and have poor seal swell. These are used for air compressors, hydraulics, etc. It's the Group IV (4) PAO based synthetics that make the best motor oils. They are compatible with petroleum based oils and fuels plus they have better seal swell than petroleum.
How do I know what motor oil is a Group IV (4) based PAO synthetic motor oil?
As more and more large oil companies switched their "synthetic" motor oils to the less expensive/more profitable Group III (3) base stocks it has become much easier to identify which are PAO based true synthetic. Of the large oil companies, only Mobil 1, as of this writing (12-15-2007), is still a PAO based true synthetic. The rest, including Castrol Syntec, have switched to the cheaper/more profitable Group III (3) petroleum based "synthetic" motor oil. AMSOIL Synthetic Motor Oils are PAO based true synthetic motor oils with the exception of the short oil drain XL-7500 synthetic motor oils sold at some Auto Parts Stores and Quick Oil Change Centers.
Take this quiz, then see the answers and explanations below.
Synthetic Oils True or False
- Synthetic motor oils damage seals.
- Synthetics are too thin to stay in the engine.
- Synthetics cause cars to use more oil.
- Synthetic lubricants are not compatible with petroleum.
- Synthetic lubricants are not readily available.
- Synthetic lubricants produce sludge.
- Synthetics can't be used with catalytic converters or oxygen sensors.
- Synthetics void warranties.
- Synthetics last forever.
- Synthetics are too expensive.
Myth #1: Synthetic motor oils damage seals.
Untrue. It would be foolhardy for lubricant manufacturers to build a product that is incompatible with seals. The composition of seals presents problems that both petroleum oils and synthetics must overcome. Made from elastomers, seals are inherently difficult to standardize.
Ultimately it is the additive mix in the oil that counts. Additives to control seal swell, shrinkage and hardening are required, whether it be a synthetic or petroleum product that is being produced.
Myth #2: Synthetics are too thin to stay in the engine.
Untrue. In order for a lubricant to be classified in any SAE grade (10W-30, 10W-40, etc) it has to meet certain guidelines with regard to viscosity ("thickness").
For example, it makes no difference whether it is 10W-40 petroleum or 10W-40 synthetic, at -25 degrees centigrade (-13F) and 100 degrees centigrade (212 degrees F) that oil has to maintain a standardized viscosity or it can't be rated a 10W-40.
Myth #3: Synthetics cause cars to use more oil.
Untrue. Synthetic motor oils are intended to use in mechanically sound engines, that is, engines that don't leak. In such engines oil consumption will actually be reduced. First, because of the lower volatility of synlubes. Second, because of the better sealing characteristics between piston rings and cylinder walls. And finally, because of the superior oxidation stability (i.e. resistance of synthetics against reacting with oxygen at high temperatures.)
Myth #4: Synthetic lubricants are not compatible with petroleum.
Untrue. The synthesized hydrocarbons, polyalphaolefins, diesters and other materials that form the base stocks of high quality name brand synthetics are fully compatible with petroleum oils. In the old days, some companies used untested ingredients that were not compatible, causing quality synlubes to suffer a bum rap. Fortunately, those days are long gone.
Compatibility is something to keep in mind, however, whether using petroleum oils or synthetics. It is usually best to use the same oil for topping off that you have been running in the engine. That is, it is preferable to not mix your oils, even if it is Valvoline or Quaker State you are using. The reason is this: the functions of additives blended for specific characteristics can be offset when oils with different additive packages are put together. For optimal performance, it is better to use the same oil throughout.
Myth#5: Synthetic lubricants are not readily available.
Untrue. This may have been the case two decades ago when AMSOIL and Mobil1 were the only real choices, but today nearly every major oil company has added a synthetic product to their lines. This in itself is a testament to the value synthetics offer. But, beware, many of the other "syntheitcs" are not true PAO (Polyalphaolefin) synthetics (ie: Castrol Syntec, Penzoil, etc...) they are hydroisomerized petroleum oil or an ester based synthetic blend.
Myth #6: Synthetic lubricants produce sludge
Untrue. In point of fact, synthetic motor oils are more sludge resistant than their petroleum counterparts, resisting the effects of high temperatures and oxidation. In the presence of high temperatures, two things happen. First, an oil's lighter ingredients boil off, making the oil thicker. Second, many of the complex chemicals found naturally in petroleum basestocks begin to react with each other, forming sludges, gums and varnishes. One result is a loss of fluidity at low temperatures, slowing the timely flow of oil to the engine for vital engine protection. Further negative effects of thickened oil include the restriction of oil flow to critical areas, greater wear and loss of fuel economy.
Because of their higher flash points, and their ability to withstand evaporation loss and oxidation, synthetics are much more resistant to sludge development.
Two other causes of sludge - ingested dirt and water dilution - can be a problem in any kind of oil, whether petroleum or synthetic. These are problems with the air filtration system and the cooling system resoectively, not the oil.
Myth #7: Synthetics can't be used with catalytic converters or oxygen sensors.
Untrue. There is no difference between synthetic and petroleum oils in regards to these components. Both synthetic and petroleum oils are similar compounds and neither is damaging to catalytic converters or oxygen sensors.
Myth #8: Synthetics void warranties.
Untrue. No major manufacturer of automobiles specifically bans the use of synthetic lubricants. In point of fact, increasing numbers of high performance cars are arriving on the showroom floors with synthetic motor oils as factory fill.
New vehicle warranties are based upon the use of oils meeting specific API Service Classifications (for example SG/CE). Synthetic lubricants which meet current API Service requirements are perfectly suited for use in any vehicle without affecting the validity of the new car warranty. In point of fact, in the over 25 years that AMSOIL Synthetic Lubricants have been used in extended service situations, over billions of miles of actual driving, these oils have not been faulted once for voiding an automaker's warranty.
Myth #9: Synthetics last forever.
Untrue. Although some experts feel that synthetic basestocks themselves can be used forever, it is well known that eventually the additives will falter and cause the oil to require changing. Moisture, fuel dilution and acids (the by-products of combustion) tend to use up additives in an oil, allowing degradation to occur.
However , by "topping off", additives can be replenished. Through good filtration and periodic oil analysis, synthetic motor oils protect an engine for lengths of time far beyond the capability of non-synthetics.
Myth #10: Synthetics are too expensive.
Untrue. Tests and experience have proven that synthetics can greatly extend drain intervals, provide better fuel economy, reduce engine wear and enable vehicles to operate with greater reliability. All these elements combine to make synthetic engine oils more economical that conventional non-synthetics.
In Europe, synthetics have enjoyed increasing acceptance as car buyers look first to performance and long term value rather than initial price. As more sophisticated technology places greater demands on today's motor oils, we will no doubt see an increasing re-evaluation of oil buying habits in this country as well.
So do you know which oil I prefer?
Tech Talk Dan
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